/*********************************************************************
Creates a rollback segment.
@return pointer to new rollback segment if create successful */
UNIV_INTERN
trx_rseg_t*
trx_rseg_create(void)
/*=================*/
{
mtr_t mtr;
ulint slot_no;
trx_rseg_t* rseg = NULL;
mtr_start(&mtr);
/* To obey the latching order, acquire the file space
x-latch before the kernel mutex. */
mtr_x_lock(fil_space_get_latch(TRX_SYS_SPACE, NULL), &mtr);
mutex_enter(&kernel_mutex);
slot_no = trx_sysf_rseg_find_free(&mtr);
if (slot_no != ULINT_UNDEFINED) {
ulint space;
ulint page_no;
ulint zip_size;
trx_sysf_t* sys_header;
page_no = trx_rseg_header_create(
TRX_SYS_SPACE, 0, ULINT_MAX, slot_no, &mtr);
ut_a(page_no != FIL_NULL);
ut_ad(!trx_rseg_get_on_id(slot_no));
sys_header = trx_sysf_get(&mtr);
space = trx_sysf_rseg_get_space(sys_header, slot_no, &mtr);
zip_size = space ? fil_space_get_zip_size(space) : 0;
rseg = trx_rseg_mem_create(
slot_no, space, zip_size, page_no, &mtr);
}
mutex_exit(&kernel_mutex);
mtr_commit(&mtr);
return(rseg);
}
/****************************************************************//**
Creates a rollback segment header. This function is called only when
a new rollback segment is created in the database.
@return page number of the created segment, FIL_NULL if fail */
UNIV_INTERN
ulint
trx_rseg_header_create(
/*===================*/
ulint space, /*!< in: space id */
ulint zip_size, /*!< in: compressed page size in bytes
or 0 for uncompressed pages */
ulint max_size, /*!< in: max size in pages */
ulint rseg_slot_no, /*!< in: rseg id == slot number in trx sys */
mtr_t* mtr) /*!< in: mtr */
{
ulint page_no;
trx_rsegf_t* rsegf;
trx_sysf_t* sys_header;
ulint i;
buf_block_t* block;
ut_ad(mtr);
ut_ad(mutex_own(&kernel_mutex));
ut_ad(mtr_memo_contains(mtr, fil_space_get_latch(space, NULL),
MTR_MEMO_X_LOCK));
/* Allocate a new file segment for the rollback segment */
block = fseg_create(space, 0,
TRX_RSEG + TRX_RSEG_FSEG_HEADER, mtr);
if (block == NULL) {
/* No space left */
return(FIL_NULL);
}
buf_block_dbg_add_level(block, SYNC_RSEG_HEADER_NEW);
page_no = buf_block_get_page_no(block);
/* Get the rollback segment file page */
rsegf = trx_rsegf_get_new(space, zip_size, page_no, mtr);
/* Initialize max size field */
mlog_write_ulint(rsegf + TRX_RSEG_MAX_SIZE, max_size,
MLOG_4BYTES, mtr);
/* Initialize the history list */
mlog_write_ulint(rsegf + TRX_RSEG_HISTORY_SIZE, 0, MLOG_4BYTES, mtr);
flst_init(rsegf + TRX_RSEG_HISTORY, mtr);
/* Reset the undo log slots */
for (i = 0; i < TRX_RSEG_N_SLOTS; i++) {
trx_rsegf_set_nth_undo(rsegf, i, FIL_NULL, mtr);
}
/* Add the rollback segment info to the free slot in
the trx system header */
sys_header = trx_sysf_get(mtr);
trx_sysf_rseg_set_space(sys_header, rseg_slot_no, space, mtr);
trx_sysf_rseg_set_page_no(sys_header, rseg_slot_no, page_no, mtr);
return(page_no);
}
ulint
trx_rseg_header_create(
/*===================*/
/* out: page number of the created segment,
FIL_NULL if fail */
ulint space, /* in: space id */
ulint max_size, /* in: max size in pages */
ulint* slot_no, /* out: rseg id == slot number in trx sys */
mtr_t* mtr) /* in: mtr */
{
ulint page_no;
trx_rsegf_t* rsegf;
trx_sysf_t* sys_header;
ulint i;
page_t* page;
ut_ad(mtr);
#ifdef UNIV_SYNC_DEBUG
ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */
ut_ad(mtr_memo_contains(mtr, fil_space_get_latch(space),
MTR_MEMO_X_LOCK));
sys_header = trx_sysf_get(mtr);
*slot_no = trx_sysf_rseg_find_free(mtr);
if (*slot_no == ULINT_UNDEFINED) {
return(FIL_NULL);
}
/* Allocate a new file segment for the rollback segment */
page = fseg_create(space, 0, TRX_RSEG + TRX_RSEG_FSEG_HEADER, mtr);
if (page == NULL) {
/* No space left */
return(FIL_NULL);
}
#ifdef UNIV_SYNC_DEBUG
buf_page_dbg_add_level(page, SYNC_RSEG_HEADER_NEW);
#endif /* UNIV_SYNC_DEBUG */
page_no = buf_frame_get_page_no(page);
/* Get the rollback segment file page */
rsegf = trx_rsegf_get_new(space, page_no, mtr);
/* Initialize max size field */
mlog_write_ulint(rsegf + TRX_RSEG_MAX_SIZE, max_size, MLOG_4BYTES, mtr);
/* Initialize the history list */
mlog_write_ulint(rsegf + TRX_RSEG_HISTORY_SIZE, 0, MLOG_4BYTES, mtr);
flst_init(rsegf + TRX_RSEG_HISTORY, mtr);
/* Reset the undo log slots */
for (i = 0; i < TRX_RSEG_N_SLOTS; i++) {
trx_rsegf_set_nth_undo(rsegf, i, FIL_NULL, mtr);
}
/* Add the rollback segment info to the free slot in the trx system
header */
trx_sysf_rseg_set_space(sys_header, *slot_no, space, mtr);
trx_sysf_rseg_set_page_no(sys_header, *slot_no, page_no, mtr);
return(page_no);
}
